Paper machine roll



y 1964 HORNBOSTEL 3, 31,571

* PAPER MACHINE ROLL Filed May 29. 1961 F1 g. 1 22 23 m /4 IN V EN TOR.

A/q yd l/orwbaa/e/ A ()RNEYS United States Patent C) ice 3,131,571 PAPER MACE-ERIE RGLL ioyd Hornbostel, Beloit, Wis, assignor to Beloit Corporation, a corporation of Wisconsin Filed May 29, 1961, Ser. No. 113,495 7 Claims. (Cl. 74--230.01)

The present invention relates to an improved roll assembly and more particularly to a rotatably supported roll wherein the surface has a predetermined longitudinal curvature.

The roll assembly of the present invention is particularly well adapted to use in paper making machinery for supporting travelling webs such as press and dryer felts or Woven plastic forming wires although it will be understood that the features of the invention may be employed in other environments requiring rolls of predetermined longitudinal curvatures or in environments where loads on the rolls tend to cause unwanted deflection. For example, Wire return rolls in a Fourdrinier paper machine are subject to a load tending to efiect central deflection thereof by virtue of the weight of the rolls themselves and of the Fourdrinier carried by the rolls and the tension on the Fourdrinier wire. These forces tend to deflect the roll downwardly at the center and this results in an undesirable guidance of the travelling wire and a highly undesirable flexing and pinching of the wire particularly in the case of a woven plastic forming wire. Such longitudinal deflection also occurs in rolls used for other purposes such as those carrying press and dryer felts. Further, in some instances it is desirable to provide an intentional crowning or longitudinal curvature of the roll.

A feature of the present invention is the provision of a roll assembly which is constructed to have a predetermined longitudinal curvature of any desired degree and which is not subjected to change in longitudinal curvature due to extrinsic effects of a normal load borne by the roll assembly or by normal variations in load and in a preferred arrangement the invention embodies a series of cylindrical surfaced roll sections of equal and uniform diameter positioned in axial sequence and supported on axes of rotation positioned at predetermined angles with respect to each other for forming a predetermined curvature of said series at one circumferential location, with a plurality of rotatable looped bridging members having outer surfaces spanning between the ends of surfaces of the adjacent roll sections and forming an axial continuation thereof at said circumferential location.

An object of the instant invention is to provide an improved roll assembly for supporting a load wherein the outer surface has a predetermined overall longitudinal shape or curvature with said overall curvature being substantially unaffected by normal variations in radial load applied to the roll assembly and not being subjected to the bending experienced by an elongated single roll supported at the ends only.

A further object of the invention is to provide an improved rotatable roll assembly comprised of roll segments for carrying a radial load such as applied by a travelling web wrapped over a portion of the arcuate surface of the roll assembly, wherein the need for large end bearings such as required with a single elongated unit roll is eliminated and supports are conveniently posi tioned along the length of the roll assembly without encumbering its normal operation.

A further object of the invention is to provide a supporting roll having a cylindrical outer surface formed of a series of roll sections wherein the sections present uniform continuous unbroken support surfaces between them and wherein their rotation at a uniform peripheral speed is assured.

3,131,571 Patented May 5, 1964 Other objects and advantages will become more apparent with the teaching of the principles of the present invention in connection with the disclosure of the preferred embodiment thereof in the specification, claims and drawings, in which:

FIGURE 1 is a fragmentary side elevational view of a roll assembly embodying the principles of the present invention;

FIGURE 2 is an enlarged fragmentary side elevational view, with portions in section, of the roll assembly; and

FIGURE 3 is a vertical sectional view taken substantially along line IIflII of FIGURE 2.

As shown on the drawings:

A roll assembly 10 for rotatably supporting a moving load is shown formed of a plurality of roll sections 11, 12 and 13 which are positioned in axial sequence so as to be sequentially adjacent each other with axial spaces between the ends of their cylindrical surfaces. The sections are arranged with their rotational axes at predetermined angles so as to obtain a desired longitudinal curvature of the assembly 10 at a certain circumferential location.

In the roll assembly shown, a travelling web W is supported which engages the roll assembly over an arcuate portion FIGURE 3, of the roll assembly surface, and the rotational axes of the roll sections will be arranged to obtain the desired longitudinal curvature of the assembly at the center of the arc 5.

While in the preferred embodiment of the invention the roll sections are arranged so as to obtain a longitudinal curvature of the supporting surface which is arcuate, it is also contemplated that in certain uses the roll sections will be positioned so that the longitudinal curvature is straight so as to present a straight line supporting surface and in this specialized instance the rotational axes of the roll sections will be coaxial. be appreciated therefore, that longitudinal curvature encompasses a zero or fiat curvature where the support offered by the rolls is straight or at zero curvature, and that the selected or predetermined curvature of any degree can be maintained.

The roll sections are each supported by bearings at their ends, and roll section 11 is supported by an end bearing assembly 14 at one end and by an end bearing assembly 15 at the other end. Bearing assembly 14 is rigidly mounted at 16 and bearing assembly 15 is rigidly mounted at 17 for supporting the roll section 11 at the proper rotational angle with respect to the roll section 12. The bearing assembly 15 includes a journal pin 18 which extends into a bearing sleeve 219 in the end of the roll section 11, and also includes a journal pin 19 which extends into a journal sleeve 21 into the hollow end of the roll section 12. The journal pins 18 and 1% are of course at an angle to each other in accordance with the rotational axes of the respective roll sections 11 and 12. As will be appreciated by those skilled in the art various bearing support arrangements may be employed.

The outer cylindrical surfaces are spaced from each other at their ends to form a gap therebetween, and these gaps are filled or bridged by looped travelling bridging members 22 and 23. They are of substantially identical construction and therefore only the member 22 is described in detail.

The members have a lateral substantially flat outer surface 24 which is flush with the cylindrical surfaces of the adjacent roll sections 11 and 12 so as to form a continuation thereof and so as to provide a continuous support surface for the web W carried thereon. As shown in FIG- URE 2, the cylindrical surfaces end at 25 and 26 and the ends of the fiat surface 24 of the bridging member 22 extend to the surface ends 25 and 26.

It is to To obtain a longitudinal curvature of the supporting surface of the roll assembly, the roll sections are positioned at predetermined angles and inasmuch as the roll surfaces in their preferred construction are cylindrical the assembly will present a supporting surface over the arcuate angle 5 which is a series of straight surfaces each at a slight angle to each other to present a curvature in the overall effect. The slight change in angle which occurs at the intersection of a cylindrical surface of a roll and the bridging member is sufficiently small to make substantially no difference in the support for most purposes. However, this effect may be reduced by reducing the length of the roll sections, and if desired each of the roll sections may be crowned so as to have a slight curvature and the bridging member 22 also may be slightly crowned so that a more perfect desired curvature can be obtained if necessary.

The looped bridging member 22 is preferably formed of a resilient material with sufficient firmness that it will be substantially non-yielding to loads on the outer surface 24. The lower loop of the bridging member is supported on rollers or pulleys 31 and 32 which are suitably rotatably supported, and the bridging member travels at the speeds of the roll sections 11 and 12 by frictional engagement therewith and also aids in insuring that the adjacent sections will travel at the same speed.

For supporting the bridging member radially outwardly facing tapered surfaces 27 and 28 are provided at the ends of the roll sections 11 and 12 and these have an angle the same as the angled sides 29 and 30 of the bridging member. With this tapered shape, as the load on the rolls increases the force between the surfaces increases reducing the chance of slippage, and inasmuch as the bridging member is formed of a resilient material good frictional contact is obtained.

The resilient nature of the bridging member serves an additional function in that it will be recognized that when the rotational axes of the adjacent roll sections are at an angle, the ends 25 and 26 of the cylindrical surfaces move away from each other as they approach the top of the arc when the longitudinal curvature of the roll assembly is in an upward direction, and move toward each other as the ends move down away from the center of the arc qb. This change in axial spacing between the ends of the surfaces is readily accommodated by the resiliency of the looped bridging member 22.

In operation, the roll assembly 10 is constructed with the roll sections 11, 12 and 13 at a predetermined angle with respect to each other to obtain the proper longitudinal curvature of the supporting surface as indicated by the arcuate portion at of FIGURE 3. During movement of the supporting web W the roll sections are either rotated by frictional contact with the web or driven in rotation and the spaces between the ends of the roll sections are bridged by the looped bridging members 22.

Thus it will be seen that I have provided an improved roll assembly which meets the objectives and advantages hereinabove set forth which provides a simplified strong supporting roll assembly capable of being constructed to a desired support configuration and not subject to deflection characteristics present in continuous surface support rolls heretofore available.

It is also contemplated that the support rolls may be driven in rotation such as by driving the looped bridging members so that they drive the roll sections. The bridgin g members also insure uniform peripheral speed between adjacent roll sections.

It is also contemplated that the curvature of the overall roll assembly may be made adjustable so as to be able to change the curvature. This may be accomplished, by way of example, by making the supports 17 for the bearings adjustable.

The drawings and specification present a detailed disclosure of the preferred embodiments of the invention,

specific forms disclosed, but covers all rnodifications, changes and alternative constructions and methods falling within the scope of the principles taught by the invention.

I claim as my invention: 1. A roll assembly comprising a series of cylindrically surfaced rolls of equal and uniform diameter positioned in axial sequence supported on axes of rotation at predetermined angles with respect to each other for forming a predetermined longitudinal curvature of said series at one circumferential location, and a plurality of rotatable looped bridging members having outer surfaces spanning between the ends of surfaces of adjacent rolls and forming an axial continuation thereof at said circumferential location.

2. A roll assembly comprising a plurality of rotatably supported axially adjacent rolls with an axial space be tween the ends of circumferential surfaces of adjacent rolls, and a looped member having an outer surface of a circumferential length greater than the circumference of said rolls bridging the space between said roll surfaces at a circumferential location to form a continuation of the roll surfaces, said rolls being independently rotatable except for said looped member, said member frictionally engaging the surfaces between the ends of the adjacent rolls insuring rotation of the rolls at uniform speed.

3. A roll assembly comprising a plurality of rotatably supported axially adjacent rolls with an axial space between the ends of circumferential surfaces of adjacent rolls, a looped member having an outer surface of a circumferential length greater than the circumference of said rolls bridging the space between said roll surfaces at a circumferential location to form a continuation of the roll surfaces, and a radially facing surface at the ends of adjacent rolls in supporting engagement with said looped member for supporting said travelling surface at the level of said roll surfaces at said circumferential location, said looped member forming the sole rotational connection between said rolls, said member frictionally engaging said radially facing surfaces at the ends of the adjacent rolls insuring rotation of the rolls at uniform speed.

4. A roll assembly comprising a series of cylindrically surfaced rolls of equal and uniform diameter positioned in axial sequence supported on axes of rotation at predetermined angles with respect to each other for forming a predetermined longitudinal curvature of said series at one circumferential location, a plurality of rotatable looped bridging members having outer surfaces spanning between the ends of surfaces of adjacent rolls and forming an axial continuation thereof at said circumferential location, and rotatable supports for the looped bridging members supporting the members at locations other than between adjacent rolls.

5. A roll assembly comprising a plurality of rotatably supported axially adjacent rolls with an axial space between the ends of circumferential surfaces of adjacent rolls, a looped flexible belt having inwardly tapering sides and an axially extending outer surface bridging the space between the ends of the surfaces for an arcuate length thereof, and radially laterally outwardly facing surfaces at the ends of the rolls conforming to the angles of the belt side and supporting the belt so that its outer surface forms a continuation of the roll surfaces for said arcuate length, with said belt insuring uniform speed of rotation between said rolls, said rolls being free of driving attachment except for said belt.

6. A roll assembly comprising a plurality of rotatably supported axially adjacent rolls with an axial space between the ends of adjacent rolls, and bridging members having a surface bridging said space and forming a continuation of the surfaces of said adjacent rolls at the exact diameter of said rolls, said bridging members being resilient in an axial direction for accommodating relative changes in axial spacing between the ends of the rolls.

7. A roll assembly comprising a plurality of axially adj cent rotatably supported independent roll sections, and

5 a plurality of continuous looped members with one member between the ends of each adjacent roll sections frictionally engaging surfaces between the ends of adjacent roll sections insuring rotation of the roll sections at uniform speed.

References Cited in the file of this patent UNITED STATES PATENTS 2,065,080 Lee Dec. 22, 1936 6 Ricefield Feb. 14, 1939 Lorig Dec. 31, 1957 Carroll et a1 Sept. 26, 1961 FOREIGN PATENTS Italy Apr. 6, 1957 Great Britain Sept. 30, 1953 

1. A ROLL ASSEMBLY COMPRISING A SERIES OF CYLINDRICALLY SURFACED ROLLS OF EQUAL AND UNIFORM DIAMETER POSITIONED IN AXIAL SEQUENCE SUPPORTED ON AXES OF ROTATION AT PREDETERMINED ANGLES WITH RESPECT TO EACH OTHER FOR FORMING A PREDETERMINED LONGITUDINAL CURVATURE OF SAID SERIES AT ONE CIRCUMFERENTIAL LOCATION, AND A PLURALITY OF ROTATABLE LOOPED BRIDGING MEMBERS HAVING OUTER SURFACES SPANNING BETWEEN THE ENDS OF SURFACES OF ADJACENT ROLLS AND FORMING AN AXIAL CONTINUATION THEREOF AT SAID CIRCUMFERENTIAL LOCATION. 